A spinal cord stimulator (SCS) is an implanted electronic device that manages chronic pain by delivering mild electrical pulses to the spinal cord. This neuro-modulation therapy interrupts or masks pain signals, often replacing the sensation of pain with a mild tingling feeling called paresthesia. The implantation involves a surgical procedure where patient comfort and safety are priorities. Understanding the type of anesthesia used for each stage is important for anyone considering this treatment.
Understanding the Spinal Cord Stimulator Procedure
The process of receiving a spinal cord stimulator is divided into two stages: a temporary Trial Phase and the subsequent Permanent Implant. The initial trial phase is a non-surgical step designed to ensure the therapy is effective for the patient’s specific pain condition. To qualify for the permanent device, a patient must achieve a significant reduction in pain, generally 50% or more, during the trial.
The trial tests the stimulation’s efficacy over several days or up to a week using external equipment. If successful, the patient proceeds to the permanent procedure. This involves placing the stimulation leads and implanting the power source, or implantable pulse generator (IPG), beneath the skin.
Anesthesia During the Trial Phase
The minimally invasive trial phase is performed as an outpatient procedure and does not involve deep general anesthesia. This stage uses local anesthesia applied at the insertion site to numb the skin and underlying tissues. This medication prevents pain from the needle insertion used to place the temporary leads.
Patients also receive light intravenous sedation, often called Monitored Anesthesia Care (MAC) or “twilight sedation.” This sedation makes the patient relaxed and comfortable, but still easily arousable. The patient must remain conscious and cooperative during lead placement to provide real-time feedback.
Anesthesia During the Permanent Implant
The permanent SCS implantation is a more involved surgical procedure. The anesthetic approach is carefully selected to balance patient comfort with the necessity of intraoperative testing. While some parts of the surgery may use deeper sedation or general anesthesia, the most critical phase often requires the patient to be awake or under light conscious sedation. This allows the surgeon to receive immediate feedback during “mapping.”
During mapping, the surgeon applies mild electrical pulses through the leads and asks the patient to describe where the tingling sensation (paresthesia) is felt. This feedback is used to precisely position the leads, ensuring the stimulation covers the patient’s area of chronic pain. Optimal placement is essential for the long-term success of the therapy.
If the patient is fully under general anesthesia, they cannot provide this necessary feedback, which complicates lead placement. Once the leads are confirmed, the patient may receive deeper sedation or general anesthesia for the remainder of the procedure. This final stage involves connecting the leads to the IPG and implanting the device under the skin, typically in the buttocks or abdomen.
Some newer SCS systems use high-frequency stimulation and do not rely on paresthesia. These systems may allow the entire permanent procedure to be performed under general anesthesia. However, for conventional systems, conscious sedation is maintained during lead placement to ensure proper device function.
Immediate Post-Operative Expectations
Immediately following the SCS procedure, whether the trial or the permanent implant, the patient is moved to a recovery area for monitoring. The medical team observes vital signs as the effects of sedation wear off. Patients may feel groggy and experience mild discomfort or soreness at the incision site.
Pain medication is administered as needed to manage post-operative discomfort. Patients are instructed to limit activities like bending, lifting, and twisting for several weeks. This allows the leads to settle and the incision sites to heal properly. For the permanent implant, the device is usually activated or fine-tuned shortly after surgery or at the first follow-up appointment.